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IH: Electrical System

SWITCHES

INSTRUMENTS


Sportster gauges from 1957-1969 ¹⁾	Here is the speedometer used in 1957 and 1958. The “flippers” hide key switches for the ignition and lights. ²⁾	This speedometer, manufactured by AC, was used from 1959 to 1964 on both the XLH and XLCH models. The bracket shown here is for the XLH; it fits under the locomotive nacelle and the trip odometer cable and knob comes through the nacelle back panel. The XLCH models had a different bracket with the odometer reset cable knob mounting next to the speedo face. ³⁾


The so-called Smiths gauges were introduced with the 1965 models. Although the tach was, in fact, built by Smiths, the speedo was still made by AC and is identical to the earlier Speedometer except for the fact. The 120 MPH version (lower right) was used from 1965 to 1967. The 150 MPH version was introduced in 1968 in celebration of a factory tuned Sportster going 150 mph on the Bonneville salt flats. ⁴⁾	Here are all of them until at least 1978. ⁵⁾	Sportster 1957-1958 ⁶⁾

	⁷⁾
Sportster 1959-1964	Sportster 1965-1967 ⁸⁾


Sportster 1970-1973 ⁹⁾	Sportster 1974 + ¹⁰⁾	1971 XLCH ¹¹⁾

LIGHTS

Headlight

Taillight - License Light

Turn Signals

(1973-85 Simple Turn Signal Function)
These model years HD implemented a basic turn signal circuit using a bi-metallic, current/heat-controlled, Turn Signal Flasher Unit similar to those in automobiles. The 12v power wire feeds thru the Flasher and then goes to the handlebar switches. The Left or Right handlebar turn signal switch could be pressed to feed the power to the bulbs on that side of the bike. When connected to the bulbs, thus completing the circuit, the Flasher unit would supply power until the current flowing through it would heat the bi-metallic elements sufficiently to cause a break (like a circuit breaker) in the circuit. Once the flasher cooled down, the bi-metallic elements would again conduct power to the turn signal bulbs, thus causing an on-off cycle that repeated until the handlebar switch was released.

From 1973-1981, the handlebar TS switches were small pushbuttons. They were momentary contact. The turn signal only stayed flashing while the button was depressed.
From 1982-1985, the handlebar TS housings were changed, creating a larger TS button. The switches were still momentary contact, working only while the button was depressed.

(Converting to LEDs) - Because of the way these bikes were wired, you can replace the single current/heat-activated flasher with a new electronic flasher that is capable of properly flashing LEDs or Incandescent bulbs. However, the indicator light may need to be modified by grounding one side and feeding power from the right and left circuits thru diodes to the power side of the indicator.